Spinner cowl



Oct.22,1935. RCHLTON 2,018,012

SPINNER COWL Filed Feb. 9, 1935 2 Sheets-Sheet 2 INVENTOR RQLAND CHILTONATTORNEY Patented Oct. 22;1935

UNITED STATES srmnna COWL Roland Chilton, momma, N. 1., assignor, by

to, The Reed Propel! none auigmnen Inc., Garden City, N. Y a corporationof New .York

Application February a, 193:, Serial No. 055.911

8 Claims.

This invention relates to means for improving the cooling air-flow overthe radiation means of engines and is particularly adaptable for use onengines equipped with propellers as in aircraft. This inventioncomprises'an improvement over the structure disclosed in my Patent No.1,896,222, and in .my 'copen'ding application, Serial No. 539,026. Asset forth in the specifications of the documents referred to, theair-flow behind the propeller hub and the roots of the propeller bladesof aircraft engines tends to become inadequate at high engine outputsbecause these parts have little or no air-foil section and pitch, and,therefore, set up a serious radial distortion of the airflow due tocentrifugal action.

Actual test experience with the structures disclosed in the patent andapplication mentioned, has demonstrated a very substantial increase inair-flow and, therefore, in cooling, by enclosing the engine in astationary cowling and carrying out the nose of this cowling instreamline form by means of'a large hollow spinner secured for rotationwith the propeller and having a relatively small axial air intake aheadof the propeller hub. However, this experience has shown that thestresses encountered in practice on such a largespinner are extremelysevere and the present invention comprises an improved mechanicalstructure greatly increasing the strength against cantrifugal,aerodynamic and vibration loads.

A high speed member of large diameter, which is stressed principally dueto its own mass. may not be effectively reinforced by mere increase inits sectional area since its mass and centrifugal loading are therebyproportionately increased.

It, therefore, becomes necessary to resist centrifugal loads by means ofa small diameter member not subject to high centrifugal stresses due toits own mass and velocity. In this invention this requirement iscombined with the requirement of minimum obstruction to the air-flowby anovel spinner structure including a rim supported from a hub bystreamlined spokes set in pitched disposition.

An object of the invention is to provide streamlined spokes for assumingthe centrifugal loads imposed on a hollow rotating spinner cowl throughwhich air is adapted to flow.

A further object is to provide spokes which may be set with an initialtension to reduce deforms tion of the cowl under the influence ofcentrifug I oads. 'A further object is to organize the spokes men- 5tioned to assist in producing air-flow through the spinner cowl.

Further objects win become apparent from a reading of the annexedspecification and from a consideration of the drawings, in which:

w Fig. 1 is a fragmentary axial section showing when and the spinnerstructure;

Fig. 2'is anend elevation of the rear support--. ing member;

Fig. 3 is an enlarged section on' the line 3-8 of I Fig. 2; and

Fig. 4 is an enlarged section on the line 4-4 of Fig. 2. Referring firstto Fig. 1, l0 designates the front I end or nose of the engine crankcasethrough 10 which there protrudes the end of the crankshaft i2. .011 thisthere is mounted a conventional propeller hub it having the usual bladesIt, all assembled in the usual manner except that the propeller hub nutI8 is lengthened for convenient l5 application of a bar to'the usualholes 20 for tightening up. The hub is of the conventional typeequippedwith annular faces or flanges 22 and 2| at the front and rear, whichflanges are tapped for studs 26 and 28 originally intended for securing2 0 the small spinners now sometimes used. Such old type spinners,however, have been of relatively small diameter and organized forcooling air-flow over the exterior surface of the spinner, and. are

closed at their front end. 25 a In the present invention there issecured to the front face 22 of the hub I4 by the studs 26 a frontspinner member Oil comprising a hub 32 flanged inwardly at and drilledfor the aforesaid studs 28. Preferably integral with the hub 80 32 arethe arms 86 and the rim 38. The arms 3! v are given a pitcheddisposition whereby they comprise a-fan. The spinner shell III isa-one-piece spinning of sheet metal, suitably secured tothe rim 18 andcomprising with the fixed engine cowl 36 42 a streamline cowllng for theentire engine (not shown, but placed within the cowl l2) and the centralportion of the propeller comprised of blades Ii and hub l4. 7

Secured to the rear face 24 of the propeller hub I4 is the backplateassemblage shown partially in elevation in Fig. 2. This member consistsof a hub 48 secured to the propeller hub H by the previously mentionedbolts 28 and a preferably jolntless rim member I! which embraces acylin- .45

drical rear terminal portion of the spinner shell II, which may bedetachably located as by bolts l0, Figs. 2 and 3. The hub 46 and the rim48 are united by a large number of streamlined section spokes 52 securedin the respective members by tcnsioning nipples 54 to comprise astructure reminiscent of a wire wheel having a single row of spokes. Itwill be seen that the spaces between the spokes 82 afford ports oropenings for the flow of air' through the spinner to the engine. as 55set forthin my copending applications, and these spokes are further setin pitched or angular relation so as to'comprise a'large number ofairfoils or fan blades assisting the air-flow. The spokes are local-M inthe required pitched attitude by a light angular ring 56, which hasangular slots 51 conformed to the profile of the streamlined spokes asshown in enlarged detail in Fig. 4.

The pitched attitude of the spokes 52 is preferably set so that eachspoke, acting as a fan blade, will give added impetus to air passingring 48 is subject to very high centrifugal stresses due not only to itsown weight but to that portion of the shell 40 which it is designed torestrain against centrifugal force.

Initial tests with the back member comprised of a one-piece plate havingports cut out for the air-flow, leaving material in between portscomprising radial arms, showed a satisfactory structure from a strengthpoint of view, provided relatively wide arms were used. However, it wasfound that the required width .to the arms restricted the port area, andsubsequent attempts to use only a pair of arms placed behind thepropeller blades developed mechanical troubles due to inadequate supportof the rim 48. In the present structure the spokes 52 are given asubstantial initial tension at assembly whereby they relieve the ring 48of the excessive centrifugal tension experienced in the single spokedesign, while at the same time the spoke structure of this invent-ionassists instead of interferes with the airflow.

Pitched blower fan blades 58 may be secured inside the spinner tocooperate with the pitched arms 35 of the front member and the pitchedspokes 52 in .enforcing an augmented air blast over the engine withinthe fixed cowl 42.

The openings 58 in the spinner 4D for the propeller blade 16 have beenindicated (near numeral 48) as comprising closed holes. Alternatively,these openings may comprise slots extended through the extreme rear edgeof the shell 40. In the latter case the assembled propeller is removedfrom'the spinner by removing the spoked back member complete as anassemblage by withdrawing the locating bolts 50 and the bolts 28 bywhich the hub member of the assembly is secured through the propellerhub. The assembled propeller may then be withdrawn from the spinnerthrough the open-ended slots 58 after removal of the front bolts 26.

In case it is preferred to leave continuous metal in the shell back ofthe openings 58 (in the zone near the numeral 48 of Fig. 1), it becomesnecessary to split the propeller hub H in the usual way for individualwithdrawal of the blades inwardly through the openings 58 after thebackp-late assemblage of 52 has been removed in its entirety. From astructural point of view this procedure is preferred. However, therequire-- ment of quick demountability without disturbing the propellerblade settings may in practice over-' rule, but either method isobviously within the scope of the invention. I

While I have described my invention in detail in its present preferredembodiment, it will be obvious to those skilled in the art, afterunderstanding my invention,-that various changes and modifications maybe made therein without departing from the spirit or scope thereof. Iaim I in the appended claims to cover all such modifications andchanges.

What is claimed is:

1. A spinner for a propeller comprising front and rear members securedrespectively in front 10 of and behind the propeller hub, each memberhaving pitched spokes, a shell secured to both members, and vanessecured within the spinner and to said front member spokes.

2. In a spinner, a means of resisting the cenl trifugal loads of thespinner comprising a relatively small diameter hub member, a rimembracing the spinner and spokes elongated in-cross section set ininitial tension between the hub and the rim thelonger sides of saidspokes being set 10 in pitched disposition to the local airflow.

3. In a spinner for a propeller having a rim member, means forsupporting and strengthening said-rim member without obstruction toair-flow through the spinner, comprising a hub member" and streamlinedspokes tensioned between the hub member and the rim and means to locatesaid spokes in pitched disposition.

v4. In a hollow propeller spinner arranged for flow of air therethrough,a hub member, a plurality of streamlined wire spokes extending therefromand attached at their outer ends to said spinner, each said spoke havingpitched disposition to augment airflow through said spinner, and meansengaging said spokes intermediate 35 their length for retaining thepitched disposition thereof.

5. In a hollow propeller spinner, a hub member, a plurality of tensionedspokes extending therefrom and attached at their outer ends to saidspinner, ferrules for adjustably anchoring said spokes to said spinnerand hub, and means engaging all said spokes for holding them in theiradjusted position.

6. In a hollow propeller spinner, a hub member, a plurality ofstreamlined tensioned spokes extending therefrom and attached at theirouter ends to said spinner, means at the ends of said spokes foradjusting the initial tension thereof and to permit of the adjustmentthereof to a 50 pitched disposition, and means engaging said spokes foranchoring them in their pitched disposition. v

7. In a hollow propeller spinner, a hub mem-' ber, a plurality ofstreamlined tensioned spokes 55 extending therefrom and attached attheir outerends to said spinner, means at the ends of said spokes foradjusting the initial tension thereof and to permit of the adjustmentthereof to a pitched disposition, and an angularly slotted annularmember engageable with said spokes, each spoke being engageable within aslot thereof whereby said spokes are retained in pitched disposition.

8. In a' spinner for a propeller, relatively strong pitched spokesextending from the forward'portion of said spinner to the hub of saidpropeller, and auxiliary blower vanes extending rearwardly within-saidspinner, said vanes being attached to said spinner and to said spokes. 7

Y ROLAND CHILTON.

